Tool-feed device.



B. D. JACKSON.

TOOL FEED DEVICE. APPLICATION FILED Nom?, 1912. IIBNBWBD Nov. 18, 1913. 1 1 00,885.

COLUMBIA PLANOGRAPH C0.. WASHINGTON, D. c.

B. D. JACKSON.

TOOL FEED DEVICE. APPLICATION FILED NOV.7, 1912. RENEWED NOV. 18., 1913.

1,100,885, Patented June 23,1914.

2 SHEETS-SHEET 2.

coLuAmlA PLANOURAPH co..\v,\sH|NGTON. D. c.

wat e BYRON D. JACKSON, OF ERIE, PENNSYLVANIA, ASSIGNOR T0 MGDERN TOOL COMPANY, OF ERIE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TOOL-FEED DEVICE.

Specification of Letters Patent.

Patented J une 23, 191A.

Application led November 7, 1912, Serial No. 730,100. Renewed November 18, 1913. Serial No. 801,741.1..

Pennsylvania, have invented new and useful Improvements in Tool-Feed Devices, of which the following is a specification.

rlhis invention relates to tool feed devices and consists in certain improvements in the construction thereof as will be hereinafter fully described and pointed out 1n the claims.

This tool feed device is particularly adapted for the feed mechanism of grinding machines. ln such machines great accuracy is required in advancing the tool to the work and not only is it desirable that a given amount of feeding movement should be delivered to the tool but it is desirable that the feeding mechanism be so controlled as to prevent the feeding device advancing by reason of lost motion beyond that desired.

The invention is illustrated in the accompanying drawings as follows Figure 1 is a cross section of a grinding machine, showing the feeding mechanism. Fig. 2 a section on the line 2 2 in Fig. 1. Fig. 3 a plan view of the feeding mechanism detached, parts being in section to better show construction.

1 marks the grinding wheel, 2 the spindle on which the grinding wheel is mounted and 3 the bearing frame which is slidingly mounted on the slide frame L1. The slide frame 4 is carried by the main frame 5.

A projection 6 extends downwardly from the slide frame 3 and a feed rack 7 is secured to this projection by the screws 7a.

The rack engages a pinion 8, the pinion be` ing formed 1n a sleeve 9. A worm gear 10 grinding machines the feed shaft 13 is pro-V vided with automatic machinery by which the feeding movement is accomplished. While this mechanism so far as shown would fully accomplish the feeding operation the only diiiiculty is that it is impossible to entirely take up the slack so that where there is a Yfeeding movement by reason of the feed shaft the feeding movement is liable to over-run by reason of the slack the proper position to give the dimensions desired to the piece being operated upon. To avoid this diflicultyl provide the following mechanism: A movable rack 16 is slidingly mounted on the face of the rack 7, the projection 6 having the shoulder 17 and the rack 7 having the shoulder 18 for carrying the rack 16. The take-up rack 16 has an extensionl 19 in which is a spring socket 20. A spring 21 is arranged in this socket and extends from the extension 22 on the rack 7 through the socket 20 and into engagement with Va screw 23 in the end of the extension 19. rlhis spring exerts opposing pressure on the racks 7 and 16 so that there is a yielding pressure at all times tending to move the rack 16 relatively to the rack 7. The rack 16 meshes a pinion 24. The pinion 24e is fixed on a sleeve 24a. The sleeve 24- is mounted on a shaft 25 and the shaft 25 is carried in the bearings 26, the bearings 26 forming a part of a bracket 27. The bracket 27 v is secured to the slide frame 1 by means of bolts 28. A worm gear 29 is fixed on the sleeve 24a by means of a key 30 and engages a worm 31. The worm 31 is mounted on the shaft 32 and fixed against rotation relatively thereto by means of a key 33. rlhe shafts 13 and 32 are carried in bearings 33 and 311 respectively, these bearings forming a part of the bracket 27. shaft 32 and meshes a gear 36 on the feed shaft 13. The worms 12 and 31 are oppositely pitched, that is to say, one is of right-hand thread and the other of left-hand thread and the worms are arranged to operate accordingly. By following the lines of pressure exerted from the movable rack through the pinion 24, worm gear 29, worm 31 and pinions 35 and 36 it will be noted that the feed shaft will be through the action of the spring turned in a direction to take up all the slack between the worin 12 and the worm gear 10 and between the gear S and the rack 7 and that the same sides or faces of the teeth of the worm gear 10 and the rack at all times will be in engagement with the worm 12 and pinion 8. In this way there can be no over-running and at the same time this yielding pressure due to the spring will follow through and yet permit of the ready movement of the actuating A gear 35 is fixed on the or feeding mechanism in either direction. This yielding pressure will also be constantat all times but will not oppose the feeding action except as it may increase slightly in the friction of the parts. For this reason a very sensitive feed is accomplished and at the same time over-running of the feed movement is entirely obviated.

That l cla-im as new is zl. In a tool feeding device, the combination of a member to be fed; a feed rack secured to the member; a driving pinion for driving the raclr; a driving device for actuating the pinion; a take-up rack mounted to move relatively to the feed rack; a takeup pinion actuated by the take-up rack; a connection between the take-up pinion and the driving device; and a spring exerting opposing pressures on said racks, pinions and driving and connecting devices.

2. In a tool feeding device; the combination of a member to be fed; a feed rack se cured to the member; a driving pinion for driving the rack; a driving device for actuating the pinion; a cross shaft on which the driving pinion is mounted; a feed shaft; a gear connection between the feed shaft and the cross shaft; a take-up rack movable relatively to the feed rack; a pinion actuated by the take-up rack; a take-up cross shaft on which the pinion is mounted; a talre-up shaft parallel to the feed shaft; a gear connection between the take-up shaft and the take-up cross shaft; a gear connection between the taire-up shaft and the feed shaft; and a spring arranged to exert pressure through the takeup pinion, cross shaft, take-up shaft and gear connections on the driving` connections between the feed shaft and the feed rack.

3. In a tool feeding device, the combination of a member to be fed; a feed rack secured to the member; a driving pinion for driving the feed rack; a drive cross shaft on which the pinion is mounted; a worm gear on the drive cross shaft; a feed worm actuating said gear; a driving worm gear; a feed shaft on which the feed worm is mounted; a take-up rack movable relatively to the feed rack; a take-up pinion meshing the take-up rack; a take-up cross shaft on which the take-up pinion is mounted; a talreup worm gear on the take-up cross shaft; a take-up worm engaging the take-up worin gear; a take-up shaft parallel to the feed shaft on which the take-up worm is mounted; a gear connection between the take-up shaft and the feed shaft, said worms being oppositely pitched; and a spring exerting pressure through the take-up parts enumerated an d the driving connections in the feed parts enumerated.

e. In a tool feeding device; the combination of member to be fed; a feed rack secured to the member; a driving pinion for driving to the feed rack; a drive cross shaft on which the pinion is mounted; a worm gear on the drive cross shaft; a feed worm actuating said gear; a driving worm gear; a feed shaft on which the feed worm is mounted; a take-up rack movable relatively to the feed rack; a take-up pinion meshing the take-up rack; a take-up cross shaft on which the take-up pinion is mounted; a taire-up worm gear on the take-up cross shaft; a take-up worm engaging the takeup worm gear; a taleup shaft parallel to the feed shaft on which the take-up worm is mounted; a gear connection between the take-up shaft and the feed shaft, said worms being oppositely pitched; and a spring interposed between the said racks.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

BYRON D. JACKSON.

Witnesses:

B. M. HARTMAN, H. C. LORD.

Copies of this ipatent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

